Horizontal axis wind turbines comprise a rotor provided with a number of wind turbine blades—often two or three—which extend radially from a hub. The wind turbine blades have a profile transversely to the longitudinal or radial direction of the wind turbine blades. The wind turbine blades comprise a root region with a substantially circular profile closest to the hub, an airfoil region with a lift generating profile furthest away from the hub, and optionally a transition region between the root region and the airfoil region, the profile of the transition region changing gradually in the radial direction from the circular profile of the root region to the lift generating profile of the airfoil region. The lift generating profile is provided with a suction side and a pressure side as well as a leading edge and a trailing edge. Typically, the wind turbine blades are manufactured by bonding two shell parts together along a bonding region substantially following the leading edge and the trailing edge of the wind turbine blade, such that each of the shell parts represents substantially either the pressure side or the suction side. As the demand for more powerful wind turbines, e.g. longer wind turbine blades, is increasing and the demand for more cost-effective wind turbines is increasing at the same time, problems are encountered to provide blades which have sufficient structural strength and utilise the material in an optimal way. This is especially the case for the bonding region between the two shell parts forming the wind turbine blade.
EP 2 033 769 discloses a method of manufacturing a wind turbine blade, where different longitudinal parts are manufactured separately and later moulded together.
U.S. Pat. No. 4,015,035 discloses a method of forming fiber-reinforced epoxy composite scarf joints with filaments extending from mating surfaces.
EP 1 310 351 discloses a method of manufacturing a wind turbine blade in a one-shot resin infusion process.
WO 01/46582 discloses a rotor blade for a wind power installation which has a plurality of segmented elements. Said segmented elements are attached to a load transmitting box spar and are separated by elastic joints, which enable the segments to move in relation to one another, thus minimising the tensile stress in the region of the rotor blade in which the segments are located.